求教：AMBA3 AXI协议讨论

lu.li

好像版里关于AXI的讨论已经很久没有了嘛！小弟正在钻研这方面的资料，有一些概念还是不太清楚，比如请问AXI Spec里support for multiple outstanding transactions是什么意思，还有register slice是什么意思呢，希望有同样兴趣的朋友帮忙解答，谢谢拉！

austin_lin

Sorry that I'm not able to respond by Chinese, so here is my answer in English.

• Support of multiple outstanding transactions - means that you can issue more than one AXI requests (for example, issuing 4 read transactions) while the previous requested data (such as the data for first read request) is not yet available. This would not be possible under previous AHB (AMBA 2.0) protocol as AHB could only support one outstanding transaction but not more.
• Register slice - means that you can insert register at any point of logic path (this could improve the speed of critical path in your design as more registers are inserted between, so less logic level is achieved between two registers) because there is no restricted timing requirement/relationship between AXI different channels.

Cliff_1984

高手呢？

Cliff_1984

对于exclusive access操作,要监视一个ADDRESS LOCATION 是监视一个地址,还是以这个地址开始的一个BURST的一段地址呢?

songchao0621

Sorry that I'm not able to respond by Chinese, so here is my answer in English.


Support of multiple outstanding transactions - means that you can issue more than one AXI requests (for example, i ...
austin_lin 发表于 2008-7-26 19:16

回答的很清楚，谢谢！！

cllf

学习...

22053447

想請問一下 AHB 跟 AXI 的 bus clock 在實際應用上分別是設多少呢？像是 PCI 就是 33MHz

uestckaiwen

回复 2# austin_lin


    关于这个有点看不懂，就是AXI支持数据没有返回时连续发多个读命令，这样规定的合理性在哪？如可以连着读至多多少个命令，如果不用等读返回数据，那么我发一百条读命令，而从设备根本来不及处理会不会卡死。有没有什么机制保证发的读命令都会有读数据返回？困惑中。。。。

Avalon

outstanding会有个深度,互联矩阵，还是salve可以保存命令，超过此深度就会产生问题

guozhujun1

Sorry that I'm not able to respond by Chinese, so here is my answer in English.

Support of mul ...
austin_lin 发表于 2008-7-26 19:16

                               
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   这么吊？！厉害，拜服！